Zincsilite is a rare, zinc-bearing clay mineral belonging to the smectite group. It is typically found in oxidized zones of zinc deposits, often appearing as fine-grained, white to bluish, clay-like masses rather than distinct crystals.
Is this zincsilite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch zincsilite with a known reference. Zincsilite sits at Mohs 1.5-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: pearly on cleavage.
- 4Match the color rangeCompare against the expected color range: white, bluish white, greenish white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: earthy.
Often confused with
Zincsilite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads pearly on cleavage on Zincsilite and dull on Sauconite.
How to tell apart: Hemimorphite is the harder of the two (Mohs 4.5-5 vs. 1.5-2); luster reads pearly on cleavage on Zincsilite and vitreous, subpearly, adamantine, rarely silky on Hemimorphite.
Often found alongside zincsilite
Minerals reported to co-occur with zincsilite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Zn₃Si₄O₁₀(OH)₂·4H₂O
- Mohs hardness
- 1.5-2
- Density
- 2.67-2.71 g/cm³
- Streak
- White
- Luster
- Pearly on cleavage
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Earthy
- Cleavage
- {001}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the zone of oxidation of a galena-sphalerite-chalcopyrite skarn deposit, as a pseudomorph after diopside
Where rockhounds find zincsilite
Classic worldwide localities
- Batystau polymetallicdeposit, central Kazakhstan
Field-hunting tip
Where it forms: In the zone of oxidation of a galena-sphalerite-chalcopyrite skarn deposit, as a pseudomorph after diopside. If you start seeing chrysocolla, fluorite, opal in float, you are in the right ground. Typical habit: earthy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify zincsilite?+
Where is zincsilite found?+
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What rocks look like zincsilite?+
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Find zincsilite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
